ASTM standard practice produced for the examination of welds using the alternating current field measurement (ACFM) technique

摘要

The majority of countries have their own standards organisations, and these organisations produce documents that have to be complied with whenever manufacture, inspection or verification is to be carried out. In the UK this is BSI, Germany has the DIN standard, Austria has those produced by the Austrian Standards Organization ON and the USA has the American National Standards Institute, ANSI. In some cases there are topics which are not covered by National Standards; these may then be included in European Standards (CEN) or International Standards (ISO). The current status with British Standards is that if there is a CEN document then this has priority over the BSI document. This rule also applies to private company standards ie British Gas and the Electricity Board Standards, ESI. Because of this representatives of these companies have been nominated on to CEN committees through their parent National Standards Organizations, for example BSI to ensure compatibility of standards when they are produced in Europe. Committees consisting of members nominated by their parent NSOs are producing international Standards (ISO) and, once again, an attempt is being made to ensure that these will be compatible with CEN documents. In some cases there are "manufacturing routes and inspection techniques that are not included in the range of European and International Standards, and in these cases these have then to be approved by some independent body or organisation. These may be Certifying Authorities such as Lloyds Register, Det Norske Veritas, Bureau Veritas, Offshore Certification Bureau, Germanischer Lloyds, ABS or TUV.